1. Field of the Invention
The present invention relates to an image processing apparatus, an image processing method, an imaging apparatus, and a program that perform motion vector estimation (Motion Estimation (ME)) for estimating a global motion amount between two images of an image sequence.
2. Description of the Related Art
As a method which has been most frequently used to perform motion estimation, there is a block matching method.
In order to estimate global motion between images using a block matching method, the weighted average of Motion Vectors (MVs: local MVs) generated for each divided block is basically obtained across the whole screen.
Here, robustness can be improved by reducing the weight of a block of the local MV of which is not reliable (for example, refer to JP-A-5-289159 and JP-A-2006-222933).
As another motion estimation method, Lucas-Kanade method (LK method) is known (refer to An Iterative Image Registration Technique with an Application to Stereo Vision, B. D. Lucas, T. Kanade, Intl. Joint Conf. on AI, pp. 674-679, 1981).
In particular, if the LK method is used across the whole screen, global ME in which calculation execution efficiency is considerably good as compared with the block matching method can be performed.